Large cryogenic magnetocaloric effect in transition metal-based double dinitrates

• Published in: Applied physics letters 2024-12, Vol.125 (26)
• Main Authors: Chen, Zuhua, Zhang, Chengliang, Zhang, Zhengming, Lu, Haiming, Wu, Linglu, Zhang, Guochun, Tu, Heng, Li, Zhenxing, Shen, Jun, Wang, Dunhui
• Format: Article
• Language: English
• Subjects: Antiferromagnetism; Dinitrates; First principles; Magnetic measurement; Magnetic moments; Magnetic saturation; Refrigeration; Transition metals
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/5.0243733

Exploring paramagnetic salts with weak magnetic interactions and large saturation magnetic moments is of great significance in the field of cryogenic magnetic refrigeration. In this article, the first-principles calculation is performed to predict the magnetocaloric effect (MCE) of La-transition metal-based double nitrate hydrated salts. Through the comparison of the calculation results, La2Mn3(NO3)12·24H2O (LMnN) is chosen for further research on cryogenic magnetic refrigeration. The magnetic measurements reveal a weak antiferromagnetic interaction and large saturation magnetic moment of 4.95 μB of LMnN, which are consistent with theoretical calculation results. In addition, the maximum magnetic entropy change of LMnN is calculated to be 26.61 J kg−1 K−1 under a magnetic field change of 7 T at 2.5 K, which is greater than that of another double nitrate hydrated salts La2Co3(NO3)12·24H2O (LCoN). Excellent MCE verifies the rationality of first-principles calculation and suggests that LMnN is a promising hydrated paramagnetic salt for cryogenic magnetic refrigeration.